From 2172a3d8cb18724b2e77d74afd0789f2abb246e5 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Tue, 17 Jul 2018 11:13:57 +0100
Subject: [PATCH] add a comment

---
 synapse/visibility.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/synapse/visibility.py b/synapse/visibility.py
index 27061e4ad9..6209bc0cde 100644
--- a/synapse/visibility.py
+++ b/synapse/visibility.py
@@ -291,6 +291,8 @@ def filter_events_for_server(store, server_name, events):
     def include(typ, state_key):
         if typ != EventTypes.Member:
             return True
+
+        # we avoid using get_domain_from_id here for efficiency.
         idx = state_key.find(":")
         if idx == -1:
             return False